Supporting A Load On A Roof

ABSTRACT

The invention provides a system for installing a rail and closure assembly on a metal roof. The rail and closure assembly includes a supporting rail and closure structure adapted to be supported by adjacent rib elevations of the roof, and an overlying load adapted to be supported by the rail and closure structure. The rail and closure structure diverts water around the rail and closure assembly. The entire heights of the side rails, including the rail bottoms, are above the closest portions of the panel flats. At least one panel of each of the side rails faces the respective rib along the full length of the respective side rail. The rail and closure assembly also includes a lower closure. Opposing ends of the lower closure extend upwardly and interface with the ribs. The lower closure further comprises a lower flange which interfaces with a respective panel flat.

REFERENCE TO RELATED APPLICATION

This application is a Continuation application, under 35 U.S.C. 120, ofSer. No. 14/482,471, filed Sep. 10, 2014, which is a Continuation ofSer. No. 13/771,746, filed Feb. 20, 2013, now U.S. Pat. No. 8,833,009,which is a Continuation of Ser. No. 12/932,892, filed Mar. 8, 2011, nowU.S. Pat. No. 8,438,798, which is a Continuation-In-Part of Ser. No.12/572,176, filed Oct. 1, 2009, now abandoned, which is aNon-Provisional patent application of U.S. Provisional PatentApplication Ser. No. 61/102,333, filed Oct. 2, 2008, the completedisclosure of each of which is incorporated herein, in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The field of the invention is skylights systems.

Description of Related Art

Various systems are known for using curb construction for insertingskylights and smoke vents into roofs.

The most commonly used skylighting systems are those that incorporatetranslucent or transparent layers in a framework that penetrates theroof structure, so as to allow ambient daylight into the building.

In the past, roof penetrating installations have required a complexstructure beneath the roofing panels in order to support a roof curb towhich the skylight was attached. Skylight curbs are generally in theform of a preassembled box structure, that is fixed within a roofcutout. The retrofitting of such curb systems into existing roofstructure is problematic.

U.S. Pat. No. 4,296,581, to Heckelsberg, issued Oct. 27, 1981, providesan example of a roofing structure of the type that is constructed of aseries of metal panels having flanges that interlock when the panels arelaid side by side and which are subsequently tightly seamed together toconvert the individual panels into an integrated roof forming membrane.This roof structure is mounted to the purlins with clips that permit thepanels to expand or contract in response to temperature and pressurechanges, thereby minimizing roof stressing.

U.S. Pat. No. 4,703,596, to Sandow, issued Nov. 3, 1987, and titled“Grid Skylight System”, provides a grid skylight support apparatus thatincludes prefabricated grid row frames, each of which form a number ofconnected beam supports which define a number of bays. Each bay has askylight curb formed by upper flanges of the beam supports to receive apreassembled skylight unit. The sides of each grid row frame provide amating edge that can register with the mating edge of an adjacent gridrow frame during assembly. The skylights have peripheral support skirtsthat register upon each bay and a light-transmitting skylight panel tocover the peripheral support. Cross gutters on each grid row frame,which are positioned between adjacent skylights, extend at an angletoward the mating edge of the grid row frame for carrying rainwater to amain gutter channel formed by field-assembly of the mating edges of twoadjacent grid row frames. The main gutter channel includes a pair oflongitudinally extending gutter sections, each of which have a maingutter channel surface with a lower elevation than the elevation of thecross flow channel. Fasteners assemble the grid row frame mating edgestogether and form a continuous seal to prevent rainwater leakage at themating edges of adjacent grid row frames.

U.S. Pat. No. 4,520,604, to Halsey et al., issued Jun. 4, 1985, entitled“Skylight Structure”, teaches a curb structure that is dimensioned to bepassed through an opening in a roof and then attached in moistureimpervious relation to the roof from within a building interior. Askylight assembly including a frame and light transmitting membersecured to the frame is dimensioned to be passed through the opening andattached in a sealing engagement to the curb structure from within thebuilding interior for covering the opening. The skylight assembly isthen secured to the rafters and headers at an interior location. Theframe includes upper and lower clamping jaws and spaced fulcrum linksattached to the jaws for clamping the light transmitting member thereto.The lower clamping jaw includes a channel which engages and isinterlocked with the curb structure.

Other skylight systems, as contemplated in U.S. Pat. No. 4,470,230, byWeisner, provide a prefabricated skylight support curb that is formed tobe a protective packaging for the skylight during shipment and then usedas a curb for mounting the skylight on a roof. A prefabricated skylightsupport curb for supporting a skylight thereover has a bottom flangeangled, upright sides, and a top lip round the top of the sides formingan opening through the curb. A skylight is adapted to cover the openingthrough the skylight support curb when installed, and has a domedportion and an angled portion extending from the dome portion and a dripedge on the curb portion.

In another skylight system, as contemplated in U.S. Pat. No. 3,791,088,by Sandow, et al., a prefabricated multiple dome unit or skylights andcomposite is provided, wherein each multiple dome unit has several domesof transparent or translucent material mounted together on a commonframe, and wherein means are provided for assembling a plurality of suchdome units into a composite thereof on a building, with the units lappedand interfitted so as to provide a continuous drainage systemdischarging to the exterior of the units in the composite assembly.

In yet another skylight system, as contemplated in U.S. Pat. No.4,621,466, by Sonneborn et al., a flashing frame is described for roofwindows to be installed adjacent to each other with edges facing eachother in the installed position with a connecting flange of its upperflashing members extending beneath the roofing and, if need be, with itslower flashing members and required intermediary flashing members,obliquely outwardly bent connecting webs and each with a connecting barwith supporting webs which rearwardly engage the connecting webs.

In today's world of mandated energy efficiency in all types ofbuildings, the metal building industry needs a more economical and lessdetrimental way to use skylights and smoke vents to daylight theirbuildings. To ensure adequate daylighting, however, typical skylight andsmoke vent installations require multiple roof penetrations that cutthrough and remove plural major elevations in standing seam and otherroof panel profiles. These curbs create multiple opportunities for waterto enter the interior of the building, due to multiple curb locationsand the width of the curbs, as well as the challenge to effectively sealthe roof at the high ends of such curbs.

The traditional curb constructions and methods of attachment in mostcases require a complicated support structure to be installed below theroof panel which can restrict movement associated with the thermalexpansion and contraction of the metal roof due to temperature changesand the like.

SUMMARY OF THE INVENTION

The invention provides a curbless construction system for installing twoor more adjacent skylights and smoke vents end to end onto the major ribelevation of a building's metal panel roof system. Numerous roofstructures include such elevations, sometimes deemed “ribs” or“corrugations”, including the standing seam, snap seam and “R” panelroof types. The rail and closure system is fastened to the metal roofpanels along the rib structures, so that the system can move with theexpansion and contraction of the roof.

The invention utilizes elements of the roof surface structure as anintegral part of the skylight support structure. In the preferredembodiment, the system includes a rail and closure structure adapted tobe supported on a major rib elevation a metal roof, typically where arib elevation has been cut to accommodate drainage. The balance of therib is to provide structural support for the rail and closurestructures.

The invention includes a skylight adapted to be supported on the railand closure structure, and a bearing plate structure for supporting andsealing the portion of the metal roof panel where the rib elevationshave been cut away, thus preventing water accumulation at the uppersurfaces of the roof panels, thereby preventing water ingress into thebuilding.

In some embodiments, the invention provides a skylight system (includingsmoke vents) where the bearing plate structure cooperates with the railand closure assembly to close the cut away portion to water ingress.

In another embodiment, the invention provides a rail and closurestructure where the rib has been cut in only one location.

In a further embodiment, the invention provides a rail and closurestructure where the standing seam roof has trapezoidal rib elevations.

In another embodiment, the invention provides a rail and closurestructure where the metal roof is an exposed fastener roof system.

In another embodiment, the invention provides a rail and closurestructure where ribs have been cut in two locations.

In another embodiment, the invention provides a rail and closurestructure having a trapezoidal or rectangular rib elevation 8″ to 12″ oncenter.

In another embodiment, the invention provides a rail and closurestructure where the exposed fastener roof is of the type having roofpanels fastened directly to the roof purlins from the top side of theroof panel.

In another embodiment, the invention provides a rail and closurestructure where the system comprises two or more skylights supported endto end.

In another embodiment, the invention provides a rail and closurestructure where each of the skylights is about 10 feet in length.

In another embodiment, the invention provides a rail and closurestructure where the rail and closure assembly moves with the ribelevations.

In another embodiment, the invention provides a rail and closurestructure further comprising a ridge cap configured to fit over the ribelevations at the ridge of the roof.

In another embodiment, the invention provides a rail and closurestructure where a lower closure of the rail and closure structureextends across the top of the metal roof panel profile.

In another embodiment, the invention provides a rail and closurestructure where the lower closure is configured to match the roof panelsurface adjacent rib elevations for sealing.

In another embodiment, the invention provides a rail and closurestructure where the lower closure is pre-cut to match the roof surfaceand adjacent rib elevations for sealing.

In another embodiment, the invention provides a rail and closurestructure where the rail and closure structure is fastened directly tothe rib elevations using screws or rivets.

In another embodiment, the invention provides a rail and closurestructure where the rail and closure structure forms a water tight sealwith a respective rib elevation.

In a still further embodiment, the invention provides a rail and closurestructure where a portion of only one adjacent rib elevation is cut awayto accommodate drainage along the roof surface.

In another embodiment, the invention provides a rail and closurestructure where portions of two or more adjacent rib elevations are cutaway to accommodate drainage along the roof surface.

These and other features and advantages of this invention are describedin, or are apparent from, the following detailed description of variousexemplary embodiments of the apparatus and methods according to thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention and the attendantfeatures and advantages thereof may be had by reference to the followingdetailed description when considered in combination with theaccompanying drawings.

FIG. 1 is a view showing the roof profile of metal roof panels of thetype known as standing seam roof panels.

FIG. 2 is a view showing the roof profile of metal roof panels of thetype known as architectural standing seam roof panels.

FIG. 3 is a view showing the roof profile of metal roof panels of thetype commonly referred to as snap seam roof panels.

FIG. 4 is a view showing the roof profile of metal roof panels of thetype commonly referred to as exposed fastener roof panels.

FIG. 5 is a view showing the roof profile of metal roof panels of thetype commonly known as foam core panels.

FIG. 6 is a side view showing the major components of the system asinstalled on a metal panel roof.

FIG. 7 is a top plan view of the installed system, showing placement ofskylights and the direction of water flow over the roof.

FIG. 8 is a cross sectional view showing connections of the skylightframe to the rail and closures structure, and the latter affixed overthe outer surfaces of respective rib elevations of the metal panel roof.

FIG. 9 is a perspective view, partially cut away, showing internalstructure of the system as installed on the rib elevations of a metalpanel roof.

FIG. 10 is a perspective view of the upper diverter of the rail andclosure structure.

FIG. 11 is a top view of the upper diverter of the rail and closurestructure.

FIG. 12 is a front elevation view of the upper diverter of the rail andclosure structure.

FIG. 13 is a perspective view of the lower closure of the rail andclosure structure.

FIG. 14 is a top view of the lower closure of the rail and closurestructure.

FIG. 15 is a front elevation view of the lower closure of the rail andclosure structure.

FIG. 16 is a perspective and partially cut away view showing aconnection of adjacent skylights of the system.

FIG. 17 shows detail of how the batten connects adjacent skylights andprevents water ingress between them.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The products and methods of the present invention provide a rail andclosure structure for use in installing various roof penetratingstructures in metal panel roofs. For purposes of simplicity, “roofpenetrating structures” and “skylights” will be used interchangeably tomean various forms of roof structures installed for passage of lightand/or ventilation to the interior of the building. In the case of roofventilation, examples include simple ventilation openings, such as forroof fans, and smoke vents, which are used to allow the escape of smokethrough the roof during fires.

The number of skylights can vary from one to many structures connectingend to end, limited only by the amount of support provided by the roofstructure, which roof structure is left largely intact during theskylight installation process.

The system utilizes the major rib structure in the roof as the primarystructure supporting the skylight assembly. Typical conventionalskylight installations do not allow for continuous runs, but rather usea curb construction that is typically 2-3 times wider than the presentsystem.

The present rail and closure structure does not require a complexstructure underneath the roof panels, nor does it require a separatecurb construction to support or attach the skylight. The rail andclosure structure is overlaid onto the roof system and allows forthermal expansion and contraction of the rail and closure structure byutilizing the major profiles of the metal panel roof for support. Thisis accomplished through direct attachment of the rail and closurestructure to the major roof panel ribs.

In reference now to the figures, the system allows the installation oftwo or more adjacent skylights in an end to end fashion along the majorrib structure of a building's metal roof panel profile.

The rail and closure structure can be applied to various types of ribbedroof profiles. FIG. 1 shows the roof profile of a metal panel roof ofthe type known as the standing seam roof 10. The “standing seam” roofhas trapezoidal major ribs 12 typically 24″ to 30″ on center. Each panel10 will also include the panel flat 14, having a shoulder 16 and seamedat adjacent panels forming a standing seam 18, which is folded over andseamed to prevent water from penetrating the roof.

FIG. 2 is a view showing the roof profile of a metal roof of the typeknown as an architectural standing seam roof, produced of a series ofoverlapping architectural standing seam panels 20. Each panel 20comprises a panel flat 24, with an architectural standing seam 28 formedat the interconnecting panels.

FIG. 3 is a view showing the roof profile of a metal roof of the typecommonly referred to as an R panel or exposed fastener panel 30, witheach panel having a rib 32, and panel flat 34. Adjacent R panels aresecured to the roof through structural fasteners 35 in the panel flat,adjacent shoulder 36. The rib is formed from overlapping regions, orside laps 38, with the adjacent panels secured to each other by stitchfasteners 39. The trapezoidal major ribs of the R panel roof are mosttypically formed at 8″ to 12″ on center.

FIG. 4 is a view showing the roof profile of a metal roof of the typecommonly referred to as a snap rib seam panel roof 40. A snap seam panelroof 40 has panel flats 44 and standing seams or snap seams 48 atadjacent panels.

FIG. 5 is a view showing the roof profile of a metal panel roof of thetype commonly known as foam core panel 50, which has a rib 52, a linerpanel 53, a panel flat 54 and a foam core 57. Side laps 58 are securedby a stitch fastener 59.

The system of the invention includes a rail and closure structureadapted to be supported on the major elevations, seams, rib structures,or other structural elements of such roof profiles, where the standingstructure provides the support, and the skylight or other load issecured over an opening formed in the intervening, non-structural roofflat region.

Turning now to FIG. 6, there is shown an exemplified rail and closureassembly 100 adapted for attachment to a standing seam panel roof 110.While the following figures depict such an assembly, it will beunderstood that the components could easily be adapted, by shaping ofthe elements, for attachments to any roof system that has a profile withelevations providing a place for structural support.

Looking again to the figures, particularly FIGS. 6 and 7, there is shownsuch a standing seam panel roof 110 having structural and other elementsincluding a raised rib 112, a panel flat 114, shoulder 116 and standingseam 118. Also depicted are the ridge cap 120 of the roof structure, andcutaway regions, or gaps 122 formed to accommodate the structure, asdescribed more fully as follows.

Shown as part of the system, and exemplified in this case, is a skylight130, generally comprising a skylight frame 132 and skylight lens 134.While the figures depict a skylight, it will be understood that thesystem could also be adapted for use with any number of roof penetratingstructures, from various types of skylights to smoke vents or otherventilating structures, which can all be adapted to be supported on therail and closure structure system.

Again in reference to FIGS. 6 and 7, the system includes rail andclosure structure 140, generally comprised of side rails 142 and 144, anupper diverter 146 disposed at the rib cutaway section or gap 122, and alower closure 150. At gap 122, a plate 148 is located under the gap 122to prevent water leakage into the underlying building. In assembling therail and closure structure to a roof, plate 148 is sealed and fastenedsecurely to the roof panel supports.

FIG. 7 shows how the gap 122 in the roof rib 112 allows water flow 200along the roof surface, over plate 148, and down and away from the roofridge cap 120.

Lower closure 150 seals the lower end of the system from the elements.

In reference now to FIG. 8, there is shown a cross section through theskylight 130 region of the rail and closure assembly 100, showing thesecurement of the assembly 100 to the standing seam panel roof 110. Inparticular, FIG. 8 depicts the use of the ribs 112 to support the siderails 142 and 144. Each rail 142 or 144, has a rail upper flange orbearing surface 240 and a rail shoulder 242. The rail 142 or 144 issecured to the skylight frame 132 by a plurality of fasteners 300.

The rail shoulder 242 is shaped to fit closely over the outside of theroof rib 112, and is secured to roof rib 112 by a plurality of rivets310. Upper flanges 240 of the rails support the skylight frame 132. Asealant 330 can be applied to the upper flange to seal against thepassage of water or air.

It can be seen that the rail and closure structure 140 of the assembly100 can be produced to fit closely along the contour of the roof 110,and can be so configured to have end portions that match the contour ofthe ribs 112. The various mating surfaces of the structure 140 and theroof 110 can be sealed in various ways known to the roofing art,including caulking or tape mastic, or various rubber fittings or insertscan be used to seal any open areas of the roof panels.

In FIG. 9 a partially cut away perspective view of the rail and closureassembly 100 is used to show the support of the rail and closure systemby the standing seam panel roof 110, particularly the elevated rib 112providing the structural support. FIG. 9 shows how the rail and closurestructure incorporates the structural profile of the metal roof panels,including the elevations and ribs used in sealing adjacent panels, toprovide the support of skylights. In this fashion, the system adoptsvarious advantages of a standing seam roof.

Most standing seam roofs are seamed using various clip assemblies thatallow the roof to float, along the major elevation. Typically, the roofis fixed at the cave and allowed to expand and contract toward and awayfrom the ridge. Very wide roofs can be fixed at midspan and expand andcontract toward and away from both the cave and the ridge. The design ofthe rail and closure assembly 100 takes full advantage of the floatingfeatures of contemporary roofing structures, and when a skylight is sosecured to the roof panel elevations, the skylight assemblies themselvesare able to draw strength from the structural load bearing capacity ofthe standing seam roof profile.

Shown in FIG. 9 is the panel flat 114, rib 112 and shoulder 116, as wellas the standing seam 118. The ridge cap 120 is also shown, as well asthe gap 122 in a rib at the up-slope end of the rail and closureassembly.

The skylight 130 is supported on the rail and closure structure 140, aspreviously described.

The rail and closure structure 140 is secured by its side rails 142 and144 by a series of fasteners 300 to the skylight frame 132 and to theribs 112 by a series of rivets 310.

Adjacent the up-slope end of the rail and closure structure 140, asingle rib 112 is typically cut away to create gap 122, thereby toaccommodate drainage at the up-slope end of the system (toward ridge cap120). This is an important feature for standing seam, architecturalstanding seam and snap seam roofs. Two ribs can be cut for roofs havingan “R” panel profile.

The retained portions of rib 112 function similar to e.g. flange and webportions of an I-beam, thus to support the side rails 142 and 144 andmaintain a watertight seal along the length of the assembly. Internalportions of the ribs 112 can be removed to allow additional light fromthe skylight 130.

A single bearing plate structure 148 is used for sealing the cut awayrib. The bearing plate 148 also provides some support to link adjacentrib elevations 112, and is typically produced of steel or other materialsufficient to provide a rigid substructure to the skylight rail andclosure structure.

The rail and closure structure 140 is shaped in such a manner that theskylight can be easily fastened directly to the rail portion, withrivets or other fasteners such as screws and the like.

Looking now to FIGS. 10 through 12, an upper diverter 146 providesclosure and diversion of water around the up-slope end of the assemblyto an adjacent panel flat. Diverter 146 also provides a weather tightseal at the up-slope end of the assembly, with the plate 148. Inreference to the side rails 142 and 144 on a standing seam panel roof110, the diverter 146 generally fits the profile of the rib 112 at theregion of the cut away gap 122. The side rails 142 and 144 abut thediverter 146 and the height of the diverter 146 closely matches them inheight. The upper flange 400 of the diverter 146 acts with upper flanges240 of the side rails 142 and 144 to form the bearing surface of theskylight frame.

Lower flange 410 of diverter 146 runs along the panel flat 114. Thediverter 146 also has a diversion surface 420 and fastener holes 430along the lower flange.

At one end of diverter 146 is a rib mating surface 440 and at the otherend is a rib sealing plate 450.

FIGS. 13 through 15 show the lower closure 150 that is used to maintaina weather tight seal at the lower end of the assembly. Shown inreference to the side rails 142 and 144 in FIG. 13, lower closure 150 isadapted to fit the profile of the rib 112. The side rails 142 and 144abut lower closure 150 and the height of the lower closure 150 matchesthe heights of the side rails.

Lower closure 150 has an upper flange 500 and a lower flange 510, aswell as an upstanding closure web 520. The lower flange 510 includesfastener holes 530.

The lower closure 150 also includes rib mating surfaces 540 and 550 toprovide a tight fit along the ribs 112.

Looking now to FIGS. 16 and 17, the adaptation of the system for theapplication of multiple roof penetrating structures is described. Achief aspect of the assembly 100 is the reduction in the number of roofpenetrations required to provide daylight to the interior of astructure, as fewer, longer cuts can be made along the roof elevations.This small number of openings can be maintained along a single rib, withone continuous opening, rather than multiple openings, permitting anequal or greater amount of ambient light into the building.

In the case of standing seam roofs, the system provides the ability toremove roof panel material only in the panel flat portion of the panel.This maintains the structural integrity of the roof in that multiplesections of major panel elevations are not removed, as is done toaccommodate a “typical” curb assembly. Thus, the roof's structuralintegrity is not compromised to that extent and there are fewerpotential areas for water infiltration, in that the skylight panels canbe attached very near the ridge of the building and run to the eave,requiring water to be diverted only once near the ridge of the roofplane and only across one panel flat.

To the limited extent that cutaways are made to the elevations, theseare made small, on the order of a few inches or less, solely for thepurpose of allowing drainage past the skylights.

The rail and closure assembly 100 is particularly useful for continuousruns of skylights end to end. FIG. 16 shows how two adjacent skylightsof the rail and closure assembly 100 can be affixed along a standingseam panel roof 110. Instead of producing the lights with diverters andlower closures, where adjacent lights abut, the rail and closurestructures 140 are provided with upper and lower standing rib frames 600and 610 at adjacent ends of the adjacent structures 140. A batten 620 isprovided to secure the system 100 against the elements.

FIG. 17 is a side elevation view of the batten 620, showing how thebatten fits over the adjacent upper and lower standing rib frames 600and 610.

As one example, skylights can be produced in units of up to 10 feetlong, and connected end to end for as long a distance as necessary, aseach skylight unit is supported by the ribs of the roof profile. Thestanding rib elevation (the major corrugation) runs longitudinally alongthe length of the assembly and mates with the respective rails 142, 144along the entire length of assembly 100, regardless of the number ofadjacent structures 140. No water can enter over the top of the rail andclosure assembly.

Where it is desired that the skylight starts at the ridge of the roof, asimple flashing can be inserted under the ridge cap.

Where the ridge cap has a configuration to fit the rib elevations (majorcorrugations) in the roofing panels, a portion of the one rib may be cutout (approximately 2″), allowing the water from the roof panel above tobe diverted onto the next adjacent roof panel.

If desired, a simple rail enclosure extension could be used to increasethe height or distance between the top of the skylight frame and theroof panel, and can be adapted to simply lay over or attach to the topof the rail and closure structure. Such an extension can be produced toextend along the upper flange of the rail and closure structure, toeffectively raise the height of the skylight or smoke vent toaccommodate different skylight depths or other design features, or toaccommodate snow conditions and the like. In this fashion, the rail andclosure structure can be produced to a standard height, with upwardextensions optionally being used to elevate the overall height of thestructure for such varied purposes. Various forms for such an extensionare suitable, and the skilled artisan will understand various ways andmeans of designing and manufacturing such extension to accomplish thegoal of added height to the skylight.

While this invention has been described in conjunction with the specificembodiments outlined above, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, the preferred embodiments of the invention, as setforth above, are intended to be illustrative, not limiting. Variouschanges may be made without departing from the spirit and scope of thisinvention.

1-20. (canceled)
 21. A load system for installing a load on a metalpanel roof, such metal panel roof comprising elongate metal roof panels,each having a length and a width, such roof panels defining elevatedroof panel ribs, panel flats being disposed between such roof panelribs, said load system comprising: (a) a rail and closure structurecomprising (i) a first side rail, having first and second ends, a firstlength between the first and second ends, a first top, and a firstbottom, a first downwardly-facing surface of said first side rail beingmounted directly to a first upwardly-facing surface of a first such ribalong an entirety of the first length of said first side rail, and (ii)a second side rail, having third and fourth ends, a second lengthbetween the third and fourth ends, a second top, and a second bottom, asecond downwardly-facing surface of said second side rail being mounteddirectly to a second upwardly-facing surface of a second such rib alongan entirety of the second length of said second side rail, the bottom ofat least one of said first and second side rails, at a given point alongthe length of the respective said side rail, being spaced above anelevation of a portion of the respective panel flat which most closelyunderlies the respective said side rail at such point along the lengthof the respective said side rail; and (b) a load adapted to be supportedby said rail and closure structure.
 22. A load system as in claim 21wherein a portion of only a single such roof panel rib is cut away,leaving first and second cut rib edges, respectively up slope and downslope on such roof, and an empty space between the up-slope anddown-slope cut rib edges, at least one of the cut rib edges being spacedfrom the respective said side rail.
 23. A load system as in claim 22wherein said load comprises first and second adjacent skylightssupported end to end over a single aperture in the roof.
 24. A loadsystem as in claim 22 wherein said cut away portion of the respectiveroof panel rib is made at only one of the respective roof panel ribs towhich said side rails are directly mounted.
 25. A load system as inclaim 21 wherein said system comprises first and second adjacentskylights supported end to end over a single aperture in the roof.
 26. Aload system as in claim 21 wherein said first and second side railsoverlie said ones of such roof panel ribs along full lengths of saidfirst and second rails.
 27. A load system as in claim 21 wherein thedownwardly-facing surfaces of said first and second side rails arefastened directly to the upwardly-facing surfaces of such first andsecond ribs by screws or rivets spaced from each other along the lengthsof said first and second side rails.
 28. A load system as in claim 21,installed on a roof and overlying a roof penetration.
 29. A load systemas in claim 21 wherein said load extends upwardly above the tops of saidfirst and second side rails.
 30. A load system for installing a load ona metal panel roof, such metal panel roof comprising elongate metal roofpanels, each having a length and a width, such roof panels definingelevated roof panel ribs, panel flats being disposed between such roofpanel ribs, said load system comprising: (a) a rail and closurestructure suitable for being supported by ones of the elevated roofpanel ribs, said rail and closure structure comprising a first siderail, for mounting directly to a first such rib wherein a first bottompanel of said first side rail faces a panel of such first rib, along afull length of said first side rail, and a second side rail, formounting directly to a second such rib, wherein a second bottom panel ofsaid second side rail faces a panel of such second rib, along a fulllength of said second side rail; and (b) a load adapted to be supportedon said rail and closure structure.
 31. A load system as in claim 30wherein, when said load system is installed on such roof, a portion of asuch rib is cut away, leaving first and second cut rib edges, and aspace between the cut rib edges, one of the cut rib edges being spacedfrom a respective said rail.
 32. A load system as in claim 31 whereinonly one of the respective roof panel ribs, to which said rails aremounted, is cut away to define such space between the cut rib edges. 33.A load system as in claim 30 wherein said load system, when installed onsuch roof, comprises first and second adjacent skylights supported endto end over a single aperture in such roof.
 34. A load system as inclaim 30 wherein, when said load system is installed on such roof, saidrail and closure structure overlies adjacent ones of the roof panel ribsalong the full lengths of said first and second rails.
 35. A load systemas in claim 30, installed on a roof, said load overlying a hole in theroof.
 36. A load system for installing a load on a metal panel roof,such metal panel roof comprising elongate metal roof panels, each havinga length and a width, such roof panels having upstanding rib elevations,defining elevated roof panel ribs, at opposing sides of the respectiveroof panels, panel flats being disposed between such roof panel ribelevations, said load system comprising: (a) a rail and closurestructure comprising (i) a first side rail, having first and secondends, a first upstanding web, a first mounting flange at a top of saidfirst upstanding web, and a first lower shoulder extending from a firstbottom of said first upstanding web, said first lower shoulder beingmounted to a first such rib, and (ii) a second side rail, having thirdand fourth ends, a second upstanding web, a second mounting flange at atop of said second upstanding web, and a second lower shoulder extendingfrom a second bottom of said second upstanding web, said second lowershoulder being mounted to a second such rib, roof panel profiles beingdefined by cross-sections extending across the widths of such roofpanels, further comprising (c) a lower closure structure having opposingupwardly-extending ends thereof, configured to interface with the metalroof panel profiles at the ribs to which said side rails are mounted,and a lower flange configured to interface with an intervening panelflat between such ribs, said lower closure further having an upstandingpanel, extending upwardly from said lower flange and extending betweensuch first and second ribs, thereby to prevent flow of water from anup-slope side of said lower closure structure to a down-slope side ofsaid lower closure structure.
 37. A load system for installing a load ona metal panel roof, such metal panel roof comprising a plurality ofelongate metal roof panels, each having a length and a width, such roofpanels defining elevated roof panel ribs, panel flats being disposedbetween such roof panel ribs, said load system comprising: (a) a railand closure structure comprising (i) a first side rail having first andsecond ends, a first length between the first and second ends, a firsttop, and a first bottom, said first side rail being mounted to a firstsuch rib along an entirety of the first length of said first side rail,(ii) a second side rail, having third and fourth ends, a second lengthbetween the third and fourth ends, a second top, and a second bottom,said second side rail being mounted to a second such rib along anentirety of the second length of said second side rail, at a given pointalong the length of each said side rail, an entirety of a height of therespective said side rail, from the bottom of said side rail to the topof said side rail, being spaced above an elevation of a portion of therespective panel flat which most closely underlies the respective saidside rail at such point along the length of the respective said siderail; and (b) a load supported by said rail and closure structure.
 38. Aload system as in claim 37, further comprising an upper diverterextending between the first and third ends of said first and second siderails, and a lower closure extending between the second and fourth endsof said first and second side rails.
 39. A load system as in claim 37wherein said load extends upwardly above the first and second tops ofsaid first and second side rails.